匹配公式（SQL'ish）对PHP数组返回true或false

Question

This is a tricky one to explain. I have an associative array which I want to run a set of rules against to return true or false.

I was wondering if there is a library somewhere allowing me to compare a rule (or set of) against an array. Almost like SQL exept I have the record, I just need to see if the SQL would return it or not.

For Example:

$subject = array('name' => 'John Smith', 'age' => '44');
$formula = "name LIKE 'John%' AND (age = 44 OR age = 45)";
if(match($formula, $subject))
return true;
else 
return false;

The subject array is NOT from a database it is actually from a form post, otherwise I would just run the SQL and if it returned the correct record then it would be true. Plus this is something that I would like to use a lot with may different associative arrays so adding to a table then running the query to get the same record back will not be possible either. Basically I can't use a database.

Answer 1

If you want an expression to be parsed as if it were SQL, then use an SQL parser....

$subject = array('name' => 'John Smith', 'age' => '44'); 
$formula = "'name' LIKE 'John%' AND ('age' = '44' OR 'age' = '45')";
$result=try_expression($subject, $formula);

function try_db_expression($subject, $formula) 
{
$keys=array_keys($subject);
$vals=array_values($subject);

foreach ($keys as $k=>$v) {
   $keys[$k]='/\b' . mysql_real_escape_string($v) . '\b/i';
}
foreach ($vals as $k=>$v) {
   $vals[$k]=mysql_real_escape_string($v);
}
$test=preg_replace($keys, $vals, $subject);
$res=mysql_query("SELECT ($test) AS evald");
if ($r=mysql_fetch_assoc($res)) return $r['evald'];
return false;
}

Basically I can't use a database

Then you'll have to build your own parser (not really - you can use PHP's eval - but you'll need to map the LIKE operator to PHP function).